Panelboard with provision for optional use with main breaker or main lugs with spaced insulators supporting main bus bars

ABSTRACT

A panelboard is constructed so that at the option of the installer either a main circuit breaker or main lugs may be utilized, with the lugs occupying the same location that would be occupied by the circuit breaker. The main lugs as well as the main circuit breaker may be mounted at either end of the main bus bars in the space between the insulators that support the bus bars.

UnIted States Patent 1191 1111 3,848,161 Clement Nov. 12, 1974 PANELBOARD WITH PROVISION FOR 3,075,039 l/l963 Kobrynerd 317/119 OPTIONAL USE WITH MAIN BREAKER 0R MAIN LUGS WITH SPACED INSULATORS 3:162:7l8 12/1964 Gunthel, Jr 339/198 N SUPPORTING MAIN BUS BARS FOREIGN PATENTS OR APPLICATIONS [75] Inventor: Ralph C. Clement, Bellefontaine,

Ohio 496,659 10/1953 Canada 339/22 B [73] Assignee: I-T-E Imperial Corporation, Spring Primary Examiner Robert schaefer House Assistant ExaminerGerald P. Tolin [22] Fil d; s 5, 1973 gittgrney, Agent, or Firm-Ostrolenk, Faber, Gerb & 21 Appl. No.: 394,442 0 [57] ABSTRACT 317/119 174/70 A panelboard is constructed so that at the option of [58] i 174/70 B. the installer either a main circuit breaker or main lugs 0 T??? G 198 may be utilized, with the lugs occupying the same Iocation that would be occupied by the circuit breaker. 56 R f Ct The main lugs as well as the main circuit breaker may 1 e erences I e be mounted at either end of the main bus bars in the UNITED STATES PATENTS space between the insulators that support the bus bars. 2,738,444 3/1956 Casey 317/119 6 Cl 7 D 2,985,710 5/l961 Davis 174/171 films rawmg gums PATENIE uuv 121974 smnor's PANELBOARD WITH PROVISION FOR OPTIONAL USE WITH MAIN BREAKER OR MAIN LUGS WITH SPACED INSULATORS SUPPORTING MAIN BUS BARS This invention relates to electric distribution panelboards in general and more particularly relates to panelboards of this type that may utilize either a main circuit breaker or main lugs.

For home and light industrial application it is often sufficient for panelboards to be energized through main lugs connected directly to the panelboard bus bars rather than being energized through a main circuit breaker. However, the dealer is required to stock two different panelboards, one for a main circuit breaker and the other for main lugs. This has proven costly to the dealers in that a good deal of money must be tied up in inventory and from a manufacturing standpoint this has been costly because different constructions were required.

In accordance with the instant invention, a single panelboard construction is provided that will accept either a main circuit breaker or main lugs at the option of the installer. The main lugs occupy the same space required for the circuit breaker, and the panelboard is constructed so that the main circuit breaker and the main lugs may be mounted at either end of the bus bars for convenience of connecting the energizing cables.

Identical insulators are provided with recesses which receive the ends of the bus bars to operatively position the latter. These insulators are also provided with apertures that are aligned with apertures in cable connectors of the main lugs to simplify routing of the energizing cables to the main lugs.

Accordingly, a primary object of the instant invention is to provide a novel construction for a panelboard that is adapted to utilize either main lugs or a main circuit breaker at the option of the installer.

Another object is to provide a panelboard of this type in which the main circuit breaker and main lugs may be mounted at either end of the main bus bars.

Still another object is to provide a panelboard of this type that is economical to manufacture.

A further object is to provide a novel main lug assem-' bly for a panelboard of this type.

These objects as well as other objects of this invention will become readily apparent after reading the following description of the accompanying drawings in which:

FIG. I is a plan view of a panelboard constructed in accordance with teachings of the instant invention with the cover removed.

FIG. 2 is an end view of the panelboard interior looking in the direction of arrows 2-2 of FIG. 1.

FIG. 3 is a side elevation of the panelboard interior looking in the direction of arrows 3-3 of FIG. 1.

FIG. 4 is an elevation of a bus bar insulator looking in the direction of arrows 44 of FIG. 1.

FIG. 5 is a front elevation of a main lug assembly.

FIG. 6 is a side elevation of the main lug assembly looking in the direction of arrows 66 of FIG. 5.

FIG. 7 is an exploded perspective of the main lug assembly.

Now referring to the figures. Panelboard 10 includes shallow panlike housing 11 having rear wall 12 in front of which interior is mounted by means of two screws 13 and four ears 14, the latter being struck forward from rear wall 12. Housing 11 is also provided with inwardly turned front lips l5, 16 along opposite forward edges thereof for securement of trim plate 17 in a manner well known to the art. Also disposed within housing 11 is neutral assembly 18 secured in front of rear wall 12 by a pair of screws 19, and positioned at the left of interior 20 as viewed in FIG. 1. At the option of the installer the complete panel 10 may be rotated to accommodate a situation requiring the neutral on the right-hand side thereof.

Interior 20 includes a pair of molded insulators 22, 23 seated on the forward surface of rear wall 12. Since insulators 22, 23 are identical only the construction of insulator 22 will be described in any detail. More particularly, insulator 22 includes main section 24 extending at right angles to rear housing wall 12. At the rear of the main section 24 are a pair of relatively short out board feet 25 and a relatively long central foot 26 all resting against the forward surface of rear wall 12. Central foot 26 is provided with clearance notch 27 through which securing screw 13 extends, and outboard feet 25 are. provided with locating recesses that receive ears 14.

Triangular stabilizing rib 28 also connects foot 26 to one surface of main section 24. The opposite surface of main section 24 is provided with rectangular recesses 31, 32 that receive the ends of rectangular main bus bars 33, 34, respectively, to operatively position these members in spaced parallel relationship in a common plane that is parallel to rear wall 12. This same surface of main section 24 is also provided with a plurality of aligned recesses 36 that receive projections (not shown) of circuit breaker mounting rib 35 to position the latter midway between bus bars 33, 34 and at right angles to rear surface 12 as well as at right angles to main sections 24 of insulators 22, 23. For a reason which will hereinafter seem obvious, main section 24 is provided with cable guide apertures 37, 38 positioned forward of recesses 31, 32 respectively.

Each of the bus bars 33, 34 is provided with means defining a plurality of circuit breaker locating or connecting points. For each of these connecting points the means comprises a threaded aperture 39. Interior 20 is adapted to mount push-push type circuit breakers 41, 42 of circuit breaker assembly 43 in the manner described in US. Pat. No. 3,344,317 issued September 26, 1967, to W. H. Edmunds for a Circuit Breaker Use Limiting Means. In addition, interior 20 is constructed to mount a pair of main lug assemblies 45, 45, one of which is shown in detail in FIGS. 5-7. More particularly, main lug assembly 45 includes formed conducting strap 46, insulating housing 47, and main lug 48. To assemble these elements main section 49 is inserted into housing 47 through the open end thereof and then out through slot 51 in the housing main wall 57, so that retaining section 52 of strap 46 is disposed within housing 47. Then screw 53, after passing through lock washer 54, passes through clearance aperture 55 in main section 49, and is received by threaded aperture 56 in lug 48 to secure the latter to the forward surface of strap 46. At this point main wall 57 is positioned between lug 48 and the forwardly turned ends 58, 59 of retaining section 52, thereby mounting housing 47 to strap 46. Threaded aperture 58 of .lug 48 receives clamping screw 61 which, in a manner well known to the art, is adapted to hold one or more wires inserted into lug 48 through clearance aperture 62 thereof. Clearance aperture 63 through main section 49 receives screw 64 that is received in threaded engagement by a bus bar aperture 39 to electrically and mechanically connect lug assembly 45 to one of the bus bars 33, 34.

it is noted that interior is so constructed that circuit breaker assembly 43 may be mounted at any of the locating points along bus bars 33, 34. However, when used as a main breaker, assembly 43 is customarily mounted adjacent to one or the other of insulators 22, 23. A pair of lug assemblies 45 may be used in place of circuit breaker assembly 43, with both assemblies requiring the same amount of panelboard space. The phantom indications of assemblies 43 and 45, 45, mounted to the same interior 20 in FIG. 1, are presented merely to illustrate the versatility of interior 20 and are not intended to illustrate ordinary operating conditions.

Although there have been described preferred embodiments of this novel invention, many variations and modifications will now be apparent to those skilled in the an. Therefore, this invention is to be limited not by the specific disclosure herein but only by the appending claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An electric distribution panel including a relatively shallow panlike housing; first and second inulsator members of substantially equal size and shape mounted in spaced relation to the rear wall of said housing and extending forward therefrom; first and second elongated main conductors extending generally parallel to each other in a common plane parallel to said rear wall; each of said insulator members including a plurality of recesses wherein the ends of the conductors are entered to provide the sole support operatively mounting the conductors to the insulator means; a circuit breaker locating and supporting rib positioned between said main conductors with the ends of said rib being supported by said insulator members; each of said main conductors, at locations spaced along the length thereof, being provided with means defining circuit breaker connecting points; each of said insulator members including first and second guide apertures positioned in the vicinity of the respective first and second main conductors and slightly forward thereof to direct energizing cables for said panel to cable receiving openings of main lug means positioned inboard of the insulating members and connected to those of said connecting points at the ends of said conductors.

2. An electric distribution panel as set forth in claim 1 in which there are first and second main lug means connected to the first and second conductors, respectively; both of said main lug means being positioned between said first and second insulator members; each of said main lug means including a cable gripping lug positioned forward of said main conductors in operative alignment with one of said guide apertures in each of said insulator members.

3. An electric distribution panel as set forth in claim 2 in which each of said main lug means is part of a subassembly that includes a conducting strap abutting one of said conductors, said lug secured to said strap, and a hollow insulating housing member connected to said strap; said housing member being shaped and positioned to simulate a circuit breaker housing.

4. An electric distribution panel as set forth in claim 3 in which the strap is positioned forward of the conductor which it abuts; said lug positioned forward of said strap; said housing member positioned to one side of said lug, with the latter being outside the former.

5. An electric distribution panel as set forth in claim 4 in which the strap includes retaining formations disposed within said housing member; said retaining formation and said lug cooperating to retain said housing member connected to said strap.

6. An electric distribution panel asset forth in claim 2 in which the lugs are provided with cable receiving openings facing the apertures in the insulator members. l 

1. An electric distribution panel including a relatively shallow panlike housing; first and second inulsator members of substantially equal size and shape mounted in spaced relation to the rear wall of said housing and extending forward therefrom; first and second elongated main conductors extending generally parallel to each other in a common plane parallel to said rear wall; each of said insulator members including a plurality of recesses wherein the ends of the conductors are entered to provide the sole support operatively mounting the conductors to the insulator means; a circuit breaker locating and supporting rib positioned between said main conductors with the ends of said rib being supported by said insulator members; each of said main conductors, at locations spaced along the length thereof, being provided with means defining circuit breaker connecting points; each of said insulator members including first and second guide apertures positioned in the vicinity of the respective first and second main conductors and slightly forward thereof to direct energizing cables for said panel to cable receiving openings of main lug means positioned inboard of the insulating members and connected to those of said connecting points at the ends of said conductors.
 2. An electric distribution panel as set forth in claim 1 in which there are first and second main lug means connected to the first and second conductors, respectively; both of said main lug means being positioned between said first and second insulator members; each of said main lug means including a cable gripping lug positioned forward of said main conductors in operative alignment with one of said guide apertures in each of said insulator members.
 3. An electric distribution panel as set forth in claim 2 in which each of said main lug means is part of a subassembly that includes a conducting strap abutting one of said conductors, said lug secured to said strap, and a hollow insulating housing member connected to said strap; said housing member being shaped and positioned to simulate a circuit breaker housing.
 4. An electric distribution panel as set forth in claim 3 in which the strap is positioned forward of the conductor which it abuts; said lug positioned forward of said strap; said housing member positioned to one side of said lug, with the latter being outside the former.
 5. An electric distribution panel as set forth in claim 4 in which the strap includes retaining formations disposed within said housing member; said retaining formation and said lug cooperating to retain said housing member connected to said strap.
 6. An electric distribution panel as set forth in claim 2 in which the lugs are provided with cable receiving openings facing the apertures in the insulator members. 